<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        var num = 10;
        num++; //num = num +1;
        console.log(num);
        //1.前置自增和后置自增如果单独使用 效果是一样的
        //2.后置自增 口诀:先返回原值 后自加
        var age = 10;
        console.log(age++ + 10);//20
        console.log(age)//11
        console.log(age++ + age)//21
    </script>
</head>
<body>

</body>
</html>